glib-miscellaneous-macros.html

最新gtk中文资料集

<a class="indexterm" name="id2846804"></a><pre class="programlisting">if                  G_LIKELY                            ();</pre>
<p>
Hints the compiler that the expression is likely to evaluate to a true
value. The compiler may use this information for optimizations.
</p>
<div class="informalexample"><pre class="programlisting">
if (G_LIKELY (random () != 1))
  g_print ("not one");
</pre></div>
<div class="variablelist"><table border="0">
<col align="left" valign="top">
<tbody><tr>
<td><p><span class="term"><span class="emphasis"><em>Returns</em></span>&#160;:</span></p></td>
<td>the value of <em class="parameter"><code>expr</code></em>
</td>
</tr></tbody>
</table></div>
<p class="since">Since 2.2
</p>
</div>
<hr>
<div class="refsect2" lang="en">
<a name="id2846861"></a><h3>
<a name="G-UNLIKELY:CAPS"></a>G_UNLIKELY()</h3>
<a class="indexterm" name="id2846876"></a><pre class="programlisting">#define             G_UNLIKELY(expr)</pre>
<p>
Hints the compiler that the expression is unlikely to evaluate to a true
value. The compiler may use this information for optimizations.
</p>
<div class="informalexample"><pre class="programlisting">
if (G_UNLIKELY (random () == 1))
  g_print ("a random one");
</pre></div>
<div class="variablelist"><table border="0">
<col align="left" valign="top">
<tbody>
<tr>
<td><p><span class="term"><em class="parameter"><code>expr</code></em>&#160;:</span></p></td>
<td>the expression
</td>
</tr>
<tr>
<td><p><span class="term"><span class="emphasis"><em>Returns</em></span>&#160;:</span></p></td>
<td>the value of <em class="parameter"><code>expr</code></em>
</td>
</tr>
</tbody>
</table></div>
<p class="since">Since 2.2


</p>
</div>
<hr>
<div class="refsect2" lang="en">
<a name="id2846943"></a><h3>
<a name="G-STRLOC:CAPS"></a>G_STRLOC</h3>
<a class="indexterm" name="id2846956"></a><pre class="programlisting">#define             G_STRLOC</pre>
<p>
Expands to a string identifying the current code position. 
</p>
</div>
<hr>
<div class="refsect2" lang="en">
<a name="id2846972"></a><h3>
<a name="G-STRFUNC:CAPS"></a>G_STRFUNC</h3>
<a class="indexterm" name="id2846986"></a><pre class="programlisting">#define             G_STRFUNC</pre>
<p>
Expands to a string identifying the current function. 
</p>
<p class="since">Since 2.4


</p>
</div>
<hr>
<div class="refsect2" lang="en">
<a name="id2847009"></a><h3>
<a name="G-GINT16-MODIFIER:CAPS"></a>G_GINT16_MODIFIER</h3>
<a class="indexterm" name="id2847025"></a><pre class="programlisting">#define G_GINT16_MODIFIER "h"
</pre>
<p>
The platform dependent length modifier for constructing <code class="function">printf()</code> conversion
specifiers for values of type <a class="link" href="glib-Basic-Types.html#gint16"><span class="type">gint16</span></a> or <a class="link" href="glib-Basic-Types.html#guint16"><span class="type">guint16</span></a>. It is a string literal, 
but doesn't include the percent-sign, such that you can add precision and 
length modifiers between percent-sign and conversion specifier and append a 
conversion specifier.
</p>
<p>
The following example prints "0x7b";
</p>
<div class="informalexample"><pre class="programlisting">
gint16 value = 123;
g_print ("%#" G_GINT16_MODIFIER "x", value);
</pre></div>
<p>
</p>
<p class="since">Since 2.4


</p>
</div>
<hr>
<div class="refsect2" lang="en">
<a name="id2847092"></a><h3>
<a name="G-GINT16-FORMAT:CAPS"></a>G_GINT16_FORMAT</h3>
<a class="indexterm" name="id2847106"></a><pre class="programlisting">#define G_GINT16_FORMAT "hi"
</pre>
<p>
This is the platform dependent conversion specifier for scanning and
printing values of type <a class="link" href="glib-Basic-Types.html#gint16"><span class="type">gint16</span></a>. It is a string literal, but doesn't
include the percent-sign, such that you can add precision and length
modifiers between percent-sign and conversion specifier.
</p>
<p>
</p>
<div class="informalexample"><pre class="programlisting">
gint16 in;
gint32 out;
sscanf ("42", "%" G_GINT16_FORMAT, &amp;in)
out = in * 1000;
g_print ("%" G_GINT32_FORMAT, out);
</pre></div>
<p>
</p>
</div>
<hr>
<div class="refsect2" lang="en">
<a name="id2847147"></a><h3>
<a name="G-GUINT16-FORMAT:CAPS"></a>G_GUINT16_FORMAT</h3>
<a class="indexterm" name="id2847161"></a><pre class="programlisting">#define G_GUINT16_FORMAT "hu"
</pre>
<p>
This is the platform dependent conversion specifier for scanning and
printing values of type <a class="link" href="glib-Basic-Types.html#guint16"><span class="type">guint16</span></a>. See also <a class="link" href="glib-Miscellaneous-Macros.html#G-GINT16-FORMAT:CAPS"><span class="type">G_GINT16_FORMAT</span></a>.
</p>
</div>
<hr>
<div class="refsect2" lang="en">
<a name="id2847194"></a><h3>
<a name="G-GINT32-MODIFIER:CAPS"></a>G_GINT32_MODIFIER</h3>
<a class="indexterm" name="id2847210"></a><pre class="programlisting">#define G_GINT32_MODIFIER ""
</pre>
<p>
The platform dependent length modifier for constructing <code class="function">printf()</code> conversion
specifiers for values of type <a class="link" href="glib-Basic-Types.html#gint32"><span class="type">gint32</span></a> or <a class="link" href="glib-Basic-Types.html#guint32"><span class="type">guint32</span></a>. See also <a class="link" href="glib-Miscellaneous-Macros.html#G-GINT16-MODIFIER:CAPS"><span class="type">G_GINT16_MODIFIER</span></a>.
</p>
<p class="since">Since 2.4


</p>
</div>
<hr>
<div class="refsect2" lang="en">
<a name="id2847268"></a><h3>
<a name="G-GINT32-FORMAT:CAPS"></a>G_GINT32_FORMAT</h3>
<a class="indexterm" name="id2847281"></a><pre class="programlisting">#define G_GINT32_FORMAT "i"
</pre>
<p>
This is the platform dependent conversion specifier for scanning and
printing values of type <a class="link" href="glib-Basic-Types.html#gint32"><span class="type">gint32</span></a>. See also <a class="link" href="glib-Miscellaneous-Macros.html#G-GINT16-FORMAT:CAPS"><span class="type">G_GINT16_FORMAT</span></a>.
</p>
</div>
<hr>
<div class="refsect2" lang="en">
<a name="id2847314"></a><h3>
<a name="G-GUINT32-FORMAT:CAPS"></a>G_GUINT32_FORMAT</h3>
<a class="indexterm" name="id2847327"></a><pre class="programlisting">#define G_GUINT32_FORMAT "u"
</pre>
<p>
This is the platform dependent conversion specifier for scanning and
printing values of type <a class="link" href="glib-Basic-Types.html#guint32"><span class="type">guint32</span></a>. See also <a class="link" href="glib-Miscellaneous-Macros.html#G-GINT16-FORMAT:CAPS"><span class="type">G_GINT16_FORMAT</span></a>.
</p>
</div>
<hr>
<div class="refsect2" lang="en">
<a name="id2847361"></a><h3>
<a name="G-GINT64-MODIFIER:CAPS"></a>G_GINT64_MODIFIER</h3>
<a class="indexterm" name="id2847376"></a><pre class="programlisting">#define G_GINT64_MODIFIER "ll"
</pre>
<p>
The platform dependent length modifier for constructing <code class="function">printf()</code> conversion
specifiers for values of type <a class="link" href="glib-Basic-Types.html#gint64"><span class="type">gint64</span></a> or <a class="link" href="glib-Basic-Types.html#guint64"><span class="type">guint64</span></a>. See also <a class="link" href="glib-Miscellaneous-Macros.html#G-GINT16-MODIFIER:CAPS"><span class="type">G_GINT16_MODIFIER</span></a>.
</p>
<div class="note" style="margin-left: 0.5in; margin-right: 0.5in;">
<h3 class="title">Note</h3>
<p>
Some platforms do not support printing 64 bit integers,
even though the types are supported. On such platforms <a class="link" href="glib-Miscellaneous-Macros.html#G-GINT64-MODIFIER:CAPS"><span class="type">G_GINT64_MODIFIER</span></a>
is not defined.
</p>
</div>
<p class="since">Since 2.4


</p>
</div>
<hr>
<div class="refsect2" lang="en">
<a name="id2847452"></a><h3>
<a name="G-GINT64-FORMAT:CAPS"></a>G_GINT64_FORMAT</h3>
<a class="indexterm" name="id2847465"></a><pre class="programlisting">#define G_GINT64_FORMAT "lli"
</pre>
<p>
This is the platform dependent conversion specifier for scanning and
printing values of type <a class="link" href="glib-Basic-Types.html#gint64"><span class="type">gint64</span></a>. See also <a class="link" href="glib-Miscellaneous-Macros.html#G-GINT16-FORMAT:CAPS"><span class="type">G_GINT16_FORMAT</span></a>.
</p>
<div class="note" style="margin-left: 0.5in; margin-right: 0.5in;">
<h3 class="title">Note</h3>
<p>
Some platforms do not support scanning and printing 64 bit integers,
even though the types are supported. On such platforms <a class="link" href="glib-Miscellaneous-Macros.html#G-GINT64-FORMAT:CAPS"><span class="type">G_GINT64_FORMAT</span></a>
is not defined. Note that <code class="function">scanf()</code> may not support 64 bit integers, even
if <a class="link" href="glib-Miscellaneous-Macros.html#G-GINT64-FORMAT:CAPS"><span class="type">G_GINT64_FORMAT</span></a> is defined. Due to its weak error handling, <code class="function">scanf()</code> is not 
recommended for parsing anyway; consider using <code class="function">g_strtoull()</code> instead.
</p>
</div>
</div>
<hr>
<div class="refsect2" lang="en">
<a name="id2847559"></a><h3>
<a name="G-GUINT64-FORMAT:CAPS"></a>G_GUINT64_FORMAT</h3>
<a class="indexterm" name="id2847572"></a><pre class="programlisting">#define G_GUINT64_FORMAT "llu"
</pre>
<p>
This is the platform dependent conversion specifier for scanning and
printing values of type <a class="link" href="glib-Basic-Types.html#guint64"><span class="type">guint64</span></a>. See also <a class="link" href="glib-Miscellaneous-Macros.html#G-GINT16-FORMAT:CAPS"><span class="type">G_GINT16_FORMAT</span></a>.
</p>
<div class="note" style="margin-left: 0.5in; margin-right: 0.5in;">
<h3 class="title">Note</h3>
<p>
Some platforms do not support scanning and printing 64 bit integers,
even though the types are supported. On such platforms <a class="link" href="glib-Miscellaneous-Macros.html#G-GUINT64-FORMAT:CAPS"><span class="type">G_GUINT64_FORMAT</span></a>
is not defined.  Note that <code class="function">scanf()</code> may not support 64 bit integers, even
if <a class="link" href="glib-Miscellaneous-Macros.html#G-GINT64-FORMAT:CAPS"><span class="type">G_GINT64_FORMAT</span></a> is defined. Due to its weak error handling, <code class="function">scanf()</code> is not 
recommended for parsing anyway; consider using <code class="function">g_strtoull()</code> instead.
</p>
</div>
</div>
<hr>
<div class="refsect2" lang="en">
<a name="id2847665"></a><h3>
<a name="G-GSIZE-MODIFIER:CAPS"></a>G_GSIZE_MODIFIER</h3>
<a class="indexterm" name="id2847680"></a><pre class="programlisting">#define G_GSIZE_MODIFIER ""
</pre>
<p>
The platform dependent length modifier for constructing <code class="function">printf()</code> conversion
specifiers for values of type <a class="link" href="glib-Basic-Types.html#gsize"><span class="type">gsize</span></a> or <a class="link" href="glib-Basic-Types.html#gssize"><span class="type">gssize</span></a>. See also <a class="link" href="glib-Miscellaneous-Macros.html#G-GINT16-MODIFIER:CAPS"><span class="type">G_GINT16_MODIFIER</span></a>.
</p>
<p class="since">Since 2.6


</p>
</div>
<hr>
<div class="refsect2" lang="en">
<a name="id2847738"></a><h3>
<a name="G-GSIZE-FORMAT:CAPS"></a>G_GSIZE_FORMAT</h3>
<a class="indexterm" name="id2847753"></a><pre class="programlisting">#define G_GSIZE_FORMAT "u"
</pre>
<p>
This is the platform dependent conversion specifier for scanning and
printing values of type <a class="link" href="glib-Basic-Types.html#gsize"><span class="type">gsize</span></a>. See also <a class="link" href="glib-Miscellaneous-Macros.html#G-GINT16-FORMAT:CAPS"><span class="type">G_GINT16_FORMAT</span></a>.
</p>
<p class="since">Since 2.6


</p>
</div>
<hr>
<div class="refsect2" lang="en">
<a name="id2847793"></a><h3>
<a name="G-GSSIZE-FORMAT:CAPS"></a>G_GSSIZE_FORMAT</h3>
<a class="indexterm" name="id2847809"></a><pre class="programlisting">#define G_GSSIZE_FORMAT "i"
</pre>
<p>
This is the platform dependent conversion specifier for scanning and
printing values of type <a class="link" href="glib-Basic-Types.html#gssize"><span class="type">gssize</span></a>. See also <a class="link" href="glib-Miscellaneous-Macros.html#G-GINT16-FORMAT:CAPS"><span class="type">G_GINT16_FORMAT</span></a>.
</p>
<p class="since">Since 2.6


</p>
</div>
</div>
<div class="refsect1" lang="en">
<a name="id2847850"></a><div class="refsect2" lang="en"><a name="id2847851"></a></div>
<hr>
<div class="refsect2" lang="en"><a name="id2847852"></a></div>
</div>
</div>
</body>
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